[TYPO3-english] feevcal, intrati2cal localization problem

[* k-do *]

Hi, I've installed feevcal (it's almost the same than intrati2cal) and I
have a problem with the starting day in a week. It is set as the Sunday is
the first day of the week, but in my country Monday is the first day.

Anyone can give me a clue where to search in the code to modify this
behaviour? I haven't found anything to change that in the extension settings
and I think it's an important feature.

thank you very much